The present invention relates to thermal printing of colored images which uses a carrier having a repeating series of spaced dye frames of different colored dyes.
In one type of thermal printing which prints colored images, a carrier contains a repeating series of spaced frames of different colored heat transferable dyes. Such frames are often yellow, magenta, and cyan (YMC), or cyan, magenta, yellow, and black (CMYB) dye frames. In such thermal printing apparatus, the carrier is disposed between a receiver and a print head formed of, for example, a plurality of individual heating elements. When a particular heating element is actuated, it produces heat and causes dye from the carrier to transfer to the receiver. The density or darkness of printed colored dye is a function of the energy delivered from the heating element to the carrier.
Thermal dye transfer printers offer the advantage of true "continuous tone" dye density transfer. This result is obtained by varying the energy applied from each heating element, yielding a variable dye density image pixel in the receiver.
The carrier is sometimes mounted in a cartridge which includes take-up and supply spools. While some thermal printers are configured to receive carrier contained in a cartridge, not all thermal printers are so configured.
A problem is that sometimes there are defective dye frames. If a single dye frame in a series is defective, then an unsatisfactory print will be produced by the thermal printer. In addition, the color dye densities in the dye frames may vary from cartridge to cartridge. If the print head is set up for a standard series of dye frames, this also can cause less than satisfactory prints to be produced.